U.S. patent number 6,974,411 [Application Number 10/229,814] was granted by the patent office on 2005-12-13 for endoscope with single step guiding apparatus.
This patent grant is currently assigned to Neoguide Systems, Inc.. Invention is credited to Amir Belson.
United States Patent |
6,974,411 |
Belson |
December 13, 2005 |
Endoscope with single step guiding apparatus
Abstract
An endoscope with guiding apparatus is described herein. A
steerable endoscope is described having an elongate body with a
manually or selectively steerable distal portion, an automatically
controlled portion, a flexible and passively manipulated proximal
portion, and an externally controlled and manipulatable tracking
rod or guide. The tracking rod or guide is positioned within a
guide channel within the endoscope and slides relative to the
endoscope. When the guide is in a flexible state, it can conform to
a curve or path defined by the steerable distal portion and the
automatically controlled portion. The guide can then be selectively
rigidized to assume that curve or path. Once set, the endoscope can
be advanced over the rigidized guide in a monorail or "piggy-back"
fashion so that the flexible proximal portion follows the curve
held by the guide until the endoscope reaches a next point of
curvature within a body lumen.
Inventors: |
Belson; Amir (Cupertino,
CA) |
Assignee: |
Neoguide Systems, Inc. (Los
Gatos, CA)
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Family
ID: |
27791175 |
Appl.
No.: |
10/229,814 |
Filed: |
August 27, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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087100 |
Mar 1, 2002 |
6800056 |
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969927 |
Oct 2, 2001 |
6610007 |
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790204 |
Feb 20, 2001 |
6468203 |
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Current U.S.
Class: |
600/114 |
Current CPC
Class: |
A61B
1/00078 (20130101); A61B 1/0053 (20130101); A61B
1/0055 (20130101); A61B 1/31 (20130101); A61B
5/065 (20130101); A61B 1/00154 (20130101); A61B
1/008 (20130101); A61M 2025/0063 (20130101); A61B
1/015 (20130101); A61B 2034/301 (20160201) |
Current International
Class: |
A61B 001/00 () |
Field of
Search: |
;600/114,115,139,144,145,146 |
References Cited
[Referenced By]
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Primary Examiner: Flanagan; Beverly M.
Attorney, Agent or Firm: Wilson Sonsini Goodrich &
Rosati
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent
application Ser. No. 10/087,100 entitled "Endoscope with Guiding
Apparatus" filed Mar. 1, 2002, now U.S. Pat. No. 6,800,056 which is
a continuation-in-part of U.S. patent application Ser. No.
09/969,927 entitled "Steerable Segmented Endoscope and Method of
Insertion" filed Oct. 2, 2001, now U.S. Pat. No. 6,610,007 which is
a continuation-in-part of U.S. patent application Ser. No.
09/790,204 entitled "Steerable Endoscope and Improved Method of
Insertion" filed Feb. 20, 2001, now U.S. Pat. No. 6,468,203 which
claims the benefit of priority to U.S. Provisional Patent
Application Ser. No. 60/194,140 entitled the same and filed Apr. 3,
2000, all of which are incorporated herein by reference in their
entirety.
Claims
I claim:
1. A method of advancing an instrument along an arbitrary path,
comprising: selectively steering a distal portion of the instrument
to assume a selected shape along an arbitrary path such that a
portion of an elongate guide conforms to and assumes the selected
shape; advancing said instrument distally while configuring a
controllable portion of said instrument to assume the selected
shape of said distal portion, wherein said controllable portion is
proximal to said distal portion: and maintaining a position of said
guide while advancing said instrument along said guide such that a
proximal portion of said instrument assumes the selected shape
defined by said guide, wherein said instrument is freely slidable
along said guide such that advancing said instrument along said
guide is unconstrained.
2. The method of claim 1 wherein prior to maintaining a position of
said guide, further comprising advancing said instrument distally
while configuring a controllable portion of said instrument to
assume the selected shape of said distal portion, wherein said
controllable portion is proximal to said distal portion.
3. The method of claim 1 wherein maintaining the position of said
guide comprises rigidizing said guide such that said guide rigidly
assumes a position of the selected shape.
4. The method of claim 3 wherein rigidizing said guide comprises
applying tension to a tensioning member disposed within said guide
such that a plurality of adjacent segments comprising said guide
are compressed.
5. The method of claim 3 wherein rigidizing said guide comprises
applying a vacuum force within a lumen defined within said guide
such that a plurality of adjacent segments comprising said guide
are compressed.
6. The method of claim 1 further comprising withdrawing said guide
from said instrument.
7. The method of claim 1 wherein said guide is slidably located
within said instrument through a lumen defined within the
instrument.
8. A method of advancing an instrument along an arbitrary path,
comprising: providing an instrument having a proximal end, a
controllable proximal portion, and a selectively steerable distal
portion, and further providing an elongate guide having a distal
portion positioned substantially adjacent to said distal portion of
said instrument; selectively steering said distal portion of said
instrument to assume a selected shape along a desired path;
advancing said instrument distally along said desired path while
controlling said controllable proximal portion to assume the
selected shape of said distal portion such that said guide also
assumes substantially the selected shape; and maintaining a
position of said guide while advancing said instrument along said
guide such that a proximal portion of said instrument assumes the
selected shaoe defined by said guide, wherein said instrument is
freely slidable along a length of said guide such that advancing
said instrument along the guide is unconstrained.
9. A method of advancing an instrument along an arbitrary path,
comprising: providing an instrument having a proximal end, a
controllable proximal portion, and a selectively steerable distal
portion, and further providing an elongate guide having a distal
portion positioned substantially adjacent to said distal portion of
said instrument; selectively steering said distal portion of said
instrument to assume a selected shape along a desired path;
advancing said instrument distally along said desired path while
controlling said controllable proximal portion to assume the
selected shape of said distal portion such that said guide also
assumes substantially the selected shape; and maintaining a
position of said guide while advancing said instrument along said
guide such that a proximal portion of said instrument assumes the
selected shape defined by said guide, wherein said instrument is
freely slidable along said guide such that advancing said
instrument along the guide is unconstrained.
10. The method of claim 9 wherein maintaining the position of said
guide comprises rigidizing said guide such that said guide rigidly
assumes a position of the selected shape.
11. The method of claim 10 wherein rigidizing said guide comprises
applying tension to a tensioning member disposed within said guide
such that a plurality of adjacent segments comprising said guide
are compressed.
12. The method of claim 10 wherein rigidizing said guide comprises
applying a vacuum force within a lumen defined within said guide
such that a plurality of adjacent segments comprising said guide
are compressed.
13. An apparatus for insertion into a body cavity, comprising: an
elongate body having a selectively steerable distal portion adapted
to assume a selected shape along an arbitrary path, a controllable
proximal portion located proximal to said steerable distal portion,
adapted to propagate the selected shape, and a flexible proximal
portion proximal to said controllable proximal portion; and an
elongate guide having an axial length that is less than an axial
length of said elongate body, wherein said guide is configured to
conform to and selectively maintain the selected shape assumed by
said steerable distal portion, and whereby the body is freely
slidable along a length of the guide. wherein said flexible
proximal portion of said elongate body is adapted to conform to a
selected shape maintained by said guide.
14. An apparatus for insertion into a body cavity, comprising: an
elongate body having a selectively steerable distal portion adapted
to assume a selected shape along an arbitrary path, a controllable
proximal portion located proximal to said steerable distal portion,
adapted to propagate the selected shape, and a flexible proximal
portion proximal to said controllable proximal portion; and an
elongate guide having an axial length that is less than an axial
length of said elongate body, wherein said guide is configured to
conform to and selectively maintain the selected shape assumed by
said steerable distal portion; wherein said flexible proximal
portion of said elongate body is adapted to conform to a selected
shape maintained by said guide.
15. The apparatus of claim 14 wherein said axial length of said
guide is approximately equal to a combined length of said
controllable proximal portion and said steerable distal
portion.
16. The apparatus of claim 14 wherein said elongate body defines a
lumen therethrough.
17. The apparatus of claim 16 wherein said guide is slidably
disposed within said lumen.
18. The apparatus of claim 14 wherein said selectively steerable
distal portion is controllable via a control located externally of
the body cavity.
19. The apparatus of claim 14 wherein said a length of said
proximal controllable portion is approximately equal to half the
length of said elongate body.
20. The apparatus of claim 14 wherein said proximal controllable
portion comprises a plurality of pivotally connected segments.
21. The apparatus of claim 20 wherein each of said segments
comprises an actuator for propagating the selected shape along said
proximal controllable portion.
22. The apparatus of claim 21 wherein said actuator comprises a
type of motor selected from the group consisting of pneumatic,
hydraulic, electromechanical motors and drive shafts.
23. The apparatus of claim 21 wherein said actuator comprises a
tendon.
24. The apparatus of claim 14 wherein said guide is configured to
assume the selected shape when the guide is in a flexible state and
wherein said guide is further configured to maintain the selected
shape when the guide is in a rigidized state.
25. The apparatus of claim 24 wherein said guide is configured to
selectively rigidize along the length of said guide to maintain the
selected shape in the rigidized state.
26. The apparatus of claim 24 wherein the proximal section of said
guide is in communication with a guide controller for selectively
rigidizing the guide along its length.
27. The apparatus of claim 24 wherein said guide comprises a
plurality of adjacent segments each defining a channel therethrough
such that a common channel is defined through the length of the
guide.
28. The apparatus of claim 27 further comprising a tensioning
member disposed within said common channel such that applying a
force to said tensioning member compresses said adjacent segments
together.
29. The apparatus of claim 27 wherein said guide is configured to
maintain a position of said adjacent segments relative to each
other upon applying a vacuum force within said common channel.
30. The apparatus of claim 14 further comprising a suction device
for withdrawing a gas from the body cavity through the elongate
body.
31. The apparatus of claim 30 wherein the suction device is in
fluid communication with a suction port defined on an outer surface
of said elongate body.
32. The apparatus of claim 30 wherein said suction device is
controllable via a controller located externally of the body
cavity.
33. An apparatus for inserting into a body cavity comprising: an
elongate body having a proximal portion and a selectively steerable
distal portion and defining a lumen therebetween, the steerable
distal portion being configurable to assume a selected shape along
an arbitrary path; a suction device for withdrawing gas from the
body cavity and through the elongate body, wherein the suction
device is in fluid communication with a suction port defined on an
outer surface of said elongate body; an elongate guide having a
proximal section, a distal section, and a length therebetween, said
guide being slidably disposed without constraint within said lumen
along the length for selectively supporting said body, wherein said
guide is configured to conform to and selectively maintain the
selected shape assumed by said steerable distal portion, and
wherein said proximal portion of said elongate body when advanced
distally is configured to conform to the selected curve maintained
by said guide.
Description
FIELD OF THE INVENTION
The present invention relates generally to endoscopes and
endoscopic procedures. More particularly, it relates to a method
and apparatus to facilitate insertion of a flexible endoscope along
a tortuous path, such as for colonoscopic examination and
treatment.
BACKGROUND OF THE INVENTION
An endoscope is a medical instrument for visualizing the interior
of a patient's body. Endoscopes can be used for a variety of
different diagnostic and interventional procedures, including
colonoscopy, bronchoscopy, thoracoscopy, laparoscopy and video
endoscopy.
Colonoscopy is a medical procedure in which a flexible endoscope,
or colonoscope, is inserted into a patient's colon for diagnostic
examination and/or surgical treatment of the colon. A standard
colonoscope is typically 135-185 cm in length and 12-19 mm in
diameter, and includes a fiberoptic imaging bundle or a miniature
camera located at the instrument's tip, illumination fibers, one or
two instrument channels that may also be used for insufflation or
irrigation, air and water channels, and vacuum channels. The
colonoscope is inserted via the patient's anus and is advanced
through the colon, allowing direct visual examination of the colon,
the ileocecal valve and portions of the terminal ileum.
Insertion of the colonoscope is complicated by the fact that the
colon represents a tortuous and convoluted path. Considerable
manipulation of the colonoscope is often necessary to advance the
colonoscope through the colon, making the procedure more difficult
and time consuming and adding to the potential for complications,
such as intestinal perforation. Steerable colonoscopes have been
devised to facilitate selection of the correct path though the
curves of the colon. However, as the colonoscope is inserted
farther and farther into the colon, it becomes more difficult to
advance the colonoscope along the selected path. At each turn, the
wall of the colon must maintain the curve in the colonoscope. The
colonoscope rubs against the mucosal surface of the colon along the
outside of each turn. Friction and slack in the colonoscope build
up at each turn, making it more and more difficult to advance,
withdraw, and loop the colonoscope. In addition, the force against
the wall of the colon increases with the buildup of friction. In
cases of extreme tortuosity, it may become impossible to advance
the colonoscope all of the way through the colon.
Steerable endoscopes, catheters and insertion devices for medical
examination or treatment of internal body structures are described
in the following U.S. patents, the disclosures of which are hereby
incorporated by reference in their entirety: U.S. Pat. Nos.
4,543,090; 4,753,223; 5,337,732; 5,337,733; 5,383,852; 5,487,757;
5,624,381; 5,662,587; and 5,759,151.
SUMMARY OF THE INVENTION
Accordingly, an improved endoscopic apparatus is disclosed herein
for the examination of a patient's colon, other internal bodily
cavities, and any other spaces within the body with minimal
impingement upon bodily cavities or upon the walls of the organs.
The disclosed apparatus may also be employed for various surgical
treatments of those regions, e.g., insufflation, drug delivery,
biopsies, etc. A steerable endoscope having an elongate body with a
manually or selectively steerable distal portion, an automatically
controlled portion, which may be optionally omitted from the
device, a flexible and passively manipulated proximal portion, and
an externally controlled and manipulatable tracking rod or guide is
described below. The tracking rod or guide may be slidably
positioned within a guide channel or lumen within the endoscope or
it may be externally positionable such that the guide and the
endoscope may slide relative to one another along a rail or channel
located along an external surface of the endoscope.
In operation, the steerable distal portion of the endoscope may be
first advanced into a patient's rectum via the anus. The endoscope
may be simply advanced, either manually or automatically by a
motor, until the first curvature is reached. At this point, the
steerable distal portion may be actively controlled by the
physician or surgeon to attain an optimal curvature or shape for
advancement of the endoscope. The optimal curvature or shape is
considered to be the path which presents the least amount of
contact or interference from the walls of the colon. In one
variation, once the desired curvature has been determined, the
endoscope may be advanced further into the colon such that the
automatically controlled segments of controllable portion follow
the distal portion while transmitting the optimal curvature or
shape proximally down the remaining segments of the controllable
portion. The operation of the controllable segments will be
described in further detail below.
In one variation, the guide is shorter than the full length of the
endoscope, e.g., approximately the length of the controllable
portion, and this shortened guide can be preloaded through the
proximal end of the endoscope or through the handle of the
endoscope. Once the guide is inserted, it may be advanced distally
through the endoscope to the distal tip of the endoscope. As the
user advances the endoscope distally, the automatically controlled
segments of the proximal controllable portion propagate the
selected curves down the endoscope, and the guide, in its flexible
state, passively conforms to the shape of the desired pathway. Once
the endoscope has advanced to a desired position, e.g. to a depth
less than the length of the controllable portion of the endoscope,
the user can rigidize the guide and maintain it at that depth (or
axial position). The endoscope can then be further advanced
relative to the rigidized guide, sliding over the rigid guide and
along the selected pathway. Thus, the surgeon or physician only
needs to lock the guide in position once. If the controllable
region of the endoscope and the guide are each at least half of the
length of the endoscope, the entire endoscope can conform to a
selected pathway in this manner. It is also possible to reposition
the guide easily by relaxing and/or unlocking it from its rigidized
axial position and then moving the guide into its new position.
In an alternative variation, once the steerable distal portion has
been steered or positioned for advancement, the guide may be
advanced distally in its flexible state along or within the
endoscope until it reaches a distal position, i.e., preferably some
point distal of the flexible proximal portion. Regardless whether
the optional controllable portion is omitted or not from the
device, the guide may be advanced near or to the end of the distal
portion. Once the guide has been advanced, it may directly attain
and conform to the curvature or shape defined by the steerable
distal portion.
Preferably, the guide is advanced to the distal end of steerable
distal portion or, if the controllable portion is included in the
device, the guide may be advanced to the distal end of the
controllable portion, or to some point between the two portions.
The guide may be advanced to any distal position as long as a
portion of guide attains and conforms to the optimal curvature or
shape. Prior to advancing the endoscope over the guide, the guide
may be left in its flexible state or it may be optionally
rigidized, as discussed further below. If left in its flexible
state, the guide may possibly provide desirable column strength to
the endoscope as it is advanced through the colon over the guide.
It is preferable, however, that the guide is rigidized once it has
attained and conformed to the curvature. This allows the flexible
proximal portion, i.e., the passive portion, to remain flexible and
lightweight in structure. As the position of the guide is
preferably rigidized and maintained, the endoscope may then be
advanced over the guide in a monorail or "piggy-back" fashion so
that the flexible proximal portion follows the curve held by the
guide until the endoscope reaches the next point of curvature.
In some variations, the process of alternately advancing the guide
and the endoscope may be repeated to advance the entire endoscope
through the colon while the guide may be alternatively rigidized
and relaxed while being advanced distally. While the endoscope is
advanced through the colon, the physician or surgeon may stop the
advancement to examine various areas along the colon wall using,
e.g., an imaging bundle located at the distal end of the endoscope.
During such examinations, the guide may be temporarily withdrawn
from the endoscope to allow for the insertion of other tools
through the guide channel if there is no separate channel defined
within the endoscope for the guide. The guide may also be withdrawn
through the instrument to any location within the body of the
endoscope. In other words, the guide may be withdrawn partially or
removed entirely from the endoscope at any time, if desired,
because there are no constraints which may limit the travel of the
guide through the body of the endoscope. After a procedure has been
completed on the colon wall, the tool may be withdrawn from the
guide channel and the guide may be reintroduced into the endoscope
so that the endoscope may optionally be advanced once again into
the colon.
A further variation on advancing the endoscope may use multiple
guides which are alternately rigidized while being advanced
distally along a path. Although multiple guides may be used, two
guides are preferably utilized. As the endoscopic device approaches
a curvature, a first guide may be advanced in a relaxed and
flexible state towards the steerable distal end of the device.
While being advanced, the first guide preferably conforms to the
shape defined by the distal end and the first guide may be
subsequently rigidized to maintain this shape. The device may then
be advanced further distally along the pathway while riding over
the rigidized first guide.
After the device has been advanced to its new position, a second
guide may also be advanced distally in its relaxed state through
the device up to the distal end while the first guide is maintained
in its rigidized state. The second guide may then conform to the
new shape defined by the distal end of the device and become
rigidized to maintain this new shape. At this point, the first
guide is also preferably maintained in its rigid state until the
distal end of the device has been advanced further distally. The
first guide may then be relaxed and advanced while the rigidity of
the second guide provides the strength for advancing the guide.
This procedure may be repeated as necessary for negotiating the
pathway.
To withdraw the endoscope from within the colon, the procedure
above may be reversed such that the withdrawal minimally contacts
the walls of the colon. Alternatively, the guide may simply be
removed from the endoscope while leaving the endoscope within the
colon. Alternatively, the guide may be left inside the endoscope in
the relaxed mode. The endoscope may then be simply withdrawn by
pulling the proximal portion to remove the device. This method may
rub or contact the endoscope upon the walls of the colon, but any
impingement would be minimal.
The selectively steerable distal portion can be selectively steered
or bent up to a full 180.degree. bend in any direction. A
fiberoptic imaging bundle and one or more illumination fibers may
extend through the body from the proximal portion to the distal
portion. The illumination fibers are preferably in communication
with a light source, i.e., conventional light sources, which may be
positioned at some external location, or other sources such as
LEDs. Alternatively, the endoscope may be configured as a video
endoscope with a miniaturized video camera, such as a CCD camera,
positioned at the distal portion of the endoscope body. The video
camera may be used in combination with the illumination fibers.
Optionally, the body of the endoscope may also include one or two
access lumens that may optionally be used for insufflation or
irrigation, air and water channels, and vacuum channels, etc.
Generally, the body of the endoscope is highly flexible so that it
is able to bend around small diameter curves without buckling or
kinking while maintaining the various channels intact. The
endoscope can be made in a variety of other sizes and
configurations for other medical and industrial applications.
In some variations the endoscope may optionally include a suction
device that can withdraw air or other gases, e.g. gases used for
insufflating the interior of a colon. In the example of
insufflating a colon, the insufflated gas may be trapped within
regions of the colon due to the sacculation and movement of the
colon walls. To facilitate removal of these gases, the suction
device may be utilized to withdraw these trapped gases as the
endoscope is advanced or withdrawn through the colon.
The suction device may comprise a suction tube positioned within
the endoscope and connected to a suction port defined along the
endoscope outer surface at a location proximal of the distal tip.
The suction port can apply suction at some distance from the tip of
the endoscope so that the suction does not interfere with
insufflation or other activities at the distal end of the
endoscope. In one variation, the suction port is located in the
distal half of the endoscope, approximately one-quarter down the
length of the insertable portion of the endoscope, e.g., 40 to 50
cm from the steerable tip. Some variations may apply suction
continuously, while others allow the user to selectively control
application of the suction.
The optional controllable portion is composed of at least one
segment and preferably several segments which may be controllable
via a computer and/or controller located at a distance from the
endoscope. In one variation, approximately half of the length of
the endoscope is comprised of controllable segments. Each of the
segments preferably have an actuator mechanically connecting
adjacent segments to allow for the controlled motion of the
segments in space. The actuators driving the segments may include a
variety of different types of mechanisms, e.g., pneumatic, vacuum,
hydraulic, electromechanical motors, drive shafts, etc. If a
mechanism such as a flexible drive shaft were utilized, the power
for actuating the segments would preferably be developed by a
generator located at a distance from the segments, i.e., outside of
a patient during use, and in electrical and mechanical
communication with the drive shaft. Alternatively, segments could
be actuated by push-pull wires or tendons, e.g. Bowden cables, that
bend segments by distributing force across a segment, as described
in "Tendon-Driven Endoscope and Methods of Insertion" filed Aug.
27, 2002 (Ser. No. 10/229,557), which is incorporated in its
entirety by reference.
A proximal portion comprises the rest of the endoscope and
preferably a majority of the overall length of the device. The
proximal portion is preferably a flexible tubing member that may
conform to an infinite variety of shapes. It may also be covered by
a polymeric covering optionally extendable over the controllable
portion and the steerable distal portion as well to provide a
smooth transition between the controllable segments and the
flexible tubing of the proximal portion. The controllable portion
may be optionally omitted from the endoscope. A more detailed
description on the construction and operation of the segments may
be found in U.S. patent application Ser. No. 09/969,927 entitled
"Steerable Segmented Endoscope and Method of Insertion" filed Oct.
2, 2001, which has been incorporated by reference in its
entirety.
A proximal handle may be attached to the proximal end of the
proximal portion and may include imaging devices connected to the
fiberoptic imaging bundle for direct viewing and/or for connection
to a video camera or a recording device. The handle may be
connected to other devices, e.g., illumination sources and one or
several luer lock fittings for connection to various instrument
channels. The handle may also be connected to a steering control
mechanism for controlling the steerable distal portion. The handle
may optionally have the steering control mechanism integrated
directly into the handle, e.g., in the form of a joystick,
conventional disk controller using dials or wheels, etc. An axial
motion transducer may also be provided for measuring the axial
motion, i.e., the depth change, of the endoscope body as it is
advanced and withdrawn. The axial motion transducer can be made in
many possible configurations. As the body of the endoscope slides
through the transducer, it may produce a signal indicative of the
axial position of the endoscope body with respect to the fixed
point of reference. The transducer may use various methods for
measuring the axial position of the endoscope body.
The guide is generally used to impart a desired curvature initially
defined by the steerable portion and/or by the optional
controllable portion to the passive proximal portion when the
endoscope is advanced. If held or advanced into the steerable
portion, the guide is preferably advanced to or near the distal tip
of the portion. It is also used to impart some column strength to
the proximal portion in order to maintain its shape and to prevent
any buckling when axially loaded. Preferably, the guide is slidably
disposed within the length of the endoscope body and may freely
slide entirely through the passive proximal portion, through the
controllable portion, and the steerable distal portion. The extent
to which the guide may traverse through the endoscope body may be
varied and adjusted according to the application, as described
above. Furthermore, the proximal end of the guide may be routed
through a separate channel to a guide controller which may be used
to control the advancement and/or withdrawal of the guide and which
may also be used to selectively control the rigidity of the guide
as controlled by the physician.
The structure of the guide may be varied according to the desired
application. The following descriptions of the guide are presented
as possible variations and are not intended to be limiting in their
structure. For instance, the guide may be comprised of two
coaxially positioned tubes separated by a gap. Once the guide has
been placed and has assumed the desirable shape or curve, a vacuum
force may be applied to draw out the air within the gap, thereby
radially deforming one or both tubes such that they come into
contact with one another and lock their relative positions.
Another variation on the guide is one which is rigidizable by a
tensioning member. Such a guide may be comprised of a series of
individual segments which are rotatably interlocked with one
another in series. Each segment may further define a common channel
through which a tensioning member may be positioned while being
held between a proximal and a distal segment. During use, the
tensioning member may be slackened or loosened enough such that the
guide becomes flexible enough to assume a shape or curve defined by
the endoscope. When the guide is desirably situated and has assumed
a desired shape, the tensioning member may then be tensioned,
thereby drawing each segment tightly against one another to hold
the desired shape.
Another variation may use a guide which is comprised of
interlocking ball-and-socket type joints which are gasketed at
their interfaces. Such a design may utilize a vacuum pump to
selectively tighten and relax the individual segments against one
another. Other variations may include alternating cupped segments
and ball segments, a series of collinear sleeve-hemisphere
segments, as well as other designs which may interfit with one
another in series. Such a guide may be tightened and relaxed either
by tensioning members or vacuum forces.
A further variation on the guide is a coaxially aligned stiffening
member. This assembly may include a first subassembly comprising a
number of collinearly nested segments which may be held by a
tensioning member passing through each segment. The first
subassembly may be rigidized from a flexible or flaccid state by
pulling on this tensioning member. A second subassembly may
comprise a number of annular segments also collinearly held
relative to one another with one or more tensioning members passing
through each annular segment. The second subassembly preferably
defines a central area in which the first nested subassembly may be
situated coaxially within the second subassembly. The first
subassembly is preferably slidably disposed relative to the second
subassembly thereby allowing each subassembly to be alternately
advanced in a flexible state and alternately rigidized to allow the
other subassembly to be advanced. This design presents a small
cross-section relative to the endoscope or device through which it
may be advanced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a representation of a conventional endoscope in
use.
FIG. 2A shows a variation of an endoscopic device of the present
invention.
FIGS. 2B and 2C show side sectional views of another variation of
the present invention.
FIG. 3A shows a side view of an endoscopic device variation with
the outer layers removed to reveal a guiding apparatus disposed
within.
FIGS. 3B and 3C show cross-sectional views of various examples for
obstructing the guide lumen of the endoscope.
FIGS. 4A to 4C show cross-sectional views of various examples of
guiding apparatus which may be used to guide an endoscope.
FIGS. 5A and 5B show the cross-sectioned end and side views,
respectively, of a guiding apparatus with a vacuum-actuated
rigidizing variation.
FIGS. 6A and 6B show the cross-sectioned end and side views,
respectively, of a guiding apparatus with a tensioning or
pre-tensioned element for rigidizing the guide.
FIGS. 7A and 7B show the cross-sectioned end and side views,
respectively, of a guiding apparatus with a segmented
vacuum-actuated rigidizing variation.
FIGS. 8A and 8B show the cross-sectioned end and side views,
respectively, of a guiding apparatus with interconnecting jointed
segments for rigidizing the guide.
FIGS. 9A to 9C show end, side, and cross-sectioned views,
respectively, of another variation on the guiding apparatus.
FIG. 10 shows the cross-sectioned side view of another variation on
the guiding apparatus having alternating bead and sleeve
segments.
FIG. 11A shows a side view of a nested guiding apparatus which is
part of a coaxial stiffening assembly.
FIG. 11B shows a side view of an annular guiding apparatus which is
also part of the coaxial stiffening assembly.
FIG. 11C shows the combination of the guides from FIGS. 11A and
11B.
FIGS. 12A and 12B illustrate a representative example of advancing
the endoscope along a tortuous pathway using a single rigidizing
step.
FIGS. 13A to 13H illustrate a representative example of advancing
an endoscope through a patient's colon using a guiding apparatus to
assist in advancing the endoscope.
FIGS. 14A and 14B show a variation on the withdrawal of the
endoscope with or without the guiding apparatus for the selective
treatment of sites along the patient's colon.
FIGS. 15A to 15C illustrate a representative example of advancing
an endoscope through a tortuous path using the coaxial guiding
apparatus shown in FIGS. 11A to 11C.
FIGS. 16A to 16E illustrate another variation of advancing an
endoscope through a tortuous path using multiple guiding
apparatuses.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a prior art colonoscope 10 being employed for a
colonoscopic examination of a patient's colon C. The colonoscope 10
has a proximal handle 16 and an elongate body 12 with a steerable
distal portion 14. The body 12 of the colonoscope 10 has been
lubricated and inserted into the colon C via the patient's anus A.
Utilizing the steerable distal portion 14 for guidance, the body 12
of the colonoscope 10 has been maneuvered through several turns in
the patient's colon C to the ascending colon G. Typically, this
involves a considerable amount of manipulation by pushing, pulling
and rotating the colonoscope 10 from the proximal end to advance it
through the turns of the colon C. After the steerable distal
portion 14 has passed, the wall of the colon C maintains the curve
in the flexible body 12 of the colonoscope 10 as it is advanced.
Friction develops along the body 12 of the colonoscope 10 as it is
inserted, particularly at each turn in the colon C. Because of the
friction, when the user attempts to advance the colonoscope 10, the
body 12' tends to move outward at each curve, pushing against the
wall of the colon C, which exacerbates the problem by increasing
the friction and making it more difficult to advance the
colonoscope 10. On the other hand, when the colonoscope 10 is
withdrawn, the body 12" tends to move inward at each curve taking
up the slack that developed when the colonoscope 10 was advanced.
When the patient's colon C is extremely tortuous, the distal end of
the body 12 becomes unresponsive to the user's manipulations, and
eventually it may become impossible to advance the colonoscope 10
any farther. In addition to the difficulty that it presents to the
user, tortuosity of the patient's colon also increases the risk of
complications, such as intestinal perforation.
FIG. 2A shows a variation of the steerable endoscope 20 of the
present invention. The endoscope 20 has an elongate body 21 with a
manually or selectively steerable distal portion 24, an
automatically controlled portion 28, which may be optionally
omitted from the device, a flexible and passively manipulated
proximal portion 22, and an externally controlled and manipulatable
tracking rod or guide 36 which may be slidably positioned within
the endoscope 20.
The selectively steerable distal portion 24 can be selectively
steered or bent up to a full 180.degree. bend in any direction 26,
as shown in the figure. A fiberoptic imaging bundle 40 and one or
more illumination fibers 42 may extend through the body 21 from the
proximal portion 22 to the distal portion 24. Alternatively, the
endoscope 20 may be configured as a video endoscope with a
miniaturized video camera, such as a CCD camera, positioned at the
distal portion 24 of the endoscope body 21. The images from the
video camera can be transmitted to a video monitor by a
transmission cable or by wireless transmission where images may be
viewed in real-time or recorded by a recording device onto analog
recording medium, e.g., magnetic tape, or digital recording medium,
e.g., compact disc, digital tape, etc. Optionally, the body 21 of
the endoscope 20 may include one or two access lumens 38 that may
optionally be used for illumination fibers for providing a light
source, insufflation or irrigation, air and water channels, and
vacuum channels. Generally, the body 21 of the endoscope 20 is
highly flexible so that it is able to bend around small diameter
curves without buckling or kinking while maintaining the various
channels intact. When configured for use as a colonoscope, the body
21 of the endoscope 20 may range typically from 135 to 185 cm in
length and about 13-21 mm in diameter. The endoscope 20 can be made
in a variety of other sizes and configurations for other medical
and industrial applications.
The optional controllable portion 28 is composed of at least one
segment 30, and preferably several segments 30, which may be
controllable via a computer and/or controller located at a distance
from the endoscope 20. Each of the segments 30 preferably has an
actuator mechanically connecting adjacent segments 30 to allow for
the controlled motion of the segments 30 in space. The actuators
driving the segments 30 may include a variety of different types of
mechanisms, e.g., pneumatic, hydraulic, electromechanical motors,
"off board" powered drive shafts, tendons, etc. A proximal portion
22 comprises the rest of the endoscope 20 and preferably a majority
of the overall length of the device 20. Proximal portion 20 is
preferably a flexible tubing member which may conform to an
infinite variety of shapes. It may also be covered by a polymeric
covering 39 optionally extendable over controllable portion 28 and
steerable distal portion 24 as well to provide a smooth transition
between the controllable segments 30 and the flexible tubing of
proximal portion 22. The proximal portion 22 may be made from a
variety of materials such as thermoset and thermoplastic polymers
which are used for fabricating the tubing of conventional
endoscopes.
A proximal handle 32 may be attached to the proximal end of the
proximal portion 22. The handle 32 may include an ocular 33
connected to the fiberoptic imaging bundle 42 for direct viewing.
The handle 32 may otherwise have a connector for connection to a
video camera, e.g., a CCD camera, or a recording device. The handle
32 may be connected to an illumination source 43 by an illumination
cable 44 that is connected to or continuous with the illumination
fibers 42. One or several luer lock fittings 34 may be located on
the handle 32 and connected to the various instrument channels.
The handle 32 is connected to an electronic motion controller 45 by
way of a controller cable 46. A steering control 47 may be
connected to the electronic motion controller 45 by way of a second
cable 48 or it may optionally be connected directly to the handle
32. Alternatively, the handle may have the steering control
mechanism integrated directly into the handle, e.g., in the form of
a joystick, conventional disk controllers such as dials or wheels,
etc. The steering control 47 allows the user to selectively steer
or bend the selectively steerable distal portion 26 of the body 21
in the desired direction. The steering control 47 may be a joystick
controller as shown, or other known steering control mechanism. The
electronic motion controller 45 controls the motion of the
automatically controlled proximal portion 28 of the body 21. The
electronic motion controller 45 may be implemented using a motion
control program running on a microcomputer or using an
application-specific motion controller. Alternatively, the
electronic motion controller 45 may be implemented using, e.g., a
neural network controller.
An axial motion transducer 49 may be provided for measuring the
axial motion, i.e., the depth change, of the endoscope body 21 as
it is advanced and withdrawn. The axial motion transducer 49 can be
made in many possible configurations. For example, the axial motion
transducer 49 in FIG. 2A is configured as a ring 49 that may
surround the body 21 of the endoscope 20. The axial motion
transducer 49 is preferably attached to a fixed point of reference,
such as the surgical table or the insertion point for the endoscope
20 on the patient's body. As the body 21 of the endoscope 20 slides
through the axial motion transducer 49, it produces a signal
indicative of the axial position of the endoscope body 21 with
respect to the fixed point of reference and sends a signal to the
electronic motion controller 45 by telemetry or by a cable. The
axial motion transducer 49 may use optical, electronic or
mechanical methods to measure the axial position of the endoscope
body 21.
Similarly, when the endoscope body 21 is withdrawn proximally, each
time the endoscope body 21 is moved proximally by one unit, each
section in the automatically controlled proximal portion 28 is
signaled to assume the shape of the section that previously
occupied the space that it is now in. The curve propagates distally
along the length of the automatically controlled proximal portion
28 of the endoscope body 21, and the shaped curve appears to be
fixed in space, as the endoscope body 21 withdraws proximally.
Alternatively, the segments of controlled portion 28 could be made
to become flaccid and the withdrawal would then be passive.
Whenever the endoscope body 21 is advanced or withdrawn, the axial
motion transducer 49 detects the change in position and the
electronic motion controller 45 propagates the selected curves
proximally or distally along the controllable portion 28 of the
endoscope body 21 to maintain the curves in a spatially fixed
position. The axial motion transducer 49 also allows for the
incrementing of a current depth within the colon C by the measured
change in depth. This allows the endoscope body 21 to be guided
through tortuous curves without putting unnecessary force on the
wall of the colon C. As mentioned above, such a segmented body 30
within the controllable portion 28 may be actuated by a variety of
methods. One method involves the use of electromechanical motors
which may be individually mounted on each segment 30 to move the
segments 30 relative to one another. Each segment 30 preferably
defines at least one lumen running through it to provide an access
channel through which wires, optical fibers, air and/or water
channels, various endoscopic tools, or any variety of devices and
wires may be routed through.
A more detailed description on the construction and operation of
the segments may be found in U.S. patent application Ser. No.
09/969,927 entitled "Steerable Segmented Endoscope and Method of
Insertion" filed Oct. 2, 2001, which has been incorporated by
reference in its entirety.
The guide 36 is generally used to impart a desired curvature
initially defined by the steerable distal portion 24 and/or by the
optional controllable portion 28 to the passive proximal portion 22
when the endoscope 20 is advanced. If the guide 36 is advanced into
the steerable distal portion 24, guide 36 is preferably advanced to
or near the distal tip of the portion 24. The guide 36 may also be
used partly to impart some column strength to the proximal portion
22 in order to maintain its shape and to prevent any buckling when
axially loaded, such as when the endoscope 20 is advanced through a
patient's colon. Construction of an endoscope 20 with the use of
the guide 36 not only simplifies the control systems involved but
it also represents a cost efficient device. Operation of the
endoscope 20 with guide 36 will be discussed in detail below.
Preferably, the guide 36 is slidably disposed within the length of
the endoscope body 21 and may freely slide entirely through the
passive proximal portion 22, through the optional controllable
portion 28, if utilized in the endoscope, and the steerable distal
portion 24. Guide 36 may also be withdrawn through the instrument
to any location within the body of endoscope 20. Moreover, guide 36
may be removed entirely from endoscope 20, if desired e.g., to
accommodate additional working tools. In other words, there are
preferably no constraints which may limit the travel of guide 36
within the body of endoscope 20.
Guide 36 may be advanced through proximal handle 32; alternatively,
guide 36 may also be routed through a separate channel 37 dedicated
to the guide 36. Channel 37 is preferably attached to endoscope 20
near a proximal end of the instrument, such as a location off the
proximal portion 22, and leads to a guide controller 41 which may
be used to advance and/or withdraw guide 36 through endoscope 20.
Guide controller 41 may also be used to selectively rigidize and
relax guide 36 during use within a patient. Having guide controller
41 and proximal handle 32 separated may allow for the ease of use
for the physician manipulating the endoscope 20. To aid in
advancing guide 36 through endoscope 20, a pulley mechanism may be
affixed within the steerable distal portion 24 through which a pull
wire may extend over to connect the distal end of the guide 36 to a
location outside the endoscope 20 for manipulation by the
physician.
To facilitate the movement of guide 36 through endoscope body 21, a
lubricious covering or coating may be applied over at least a
majority of the length of guide 36 or onto the inner surface of the
lumen through which guide 36 traverse, or both. Such coverings may
include various polymers and plastics, e.g., PTFE, etc., which may
simply cover the guide 36 length or which may be heatshrunk,
coated, or bonded onto guide 36, depending upon the material used.
The extent to which guide 36 traverses through the endoscope body
21 may be varied and adjusted according to the application.
FIGS. 2B and 2C show sectional partial views of a variation of the
endoscope that is capable of single-step use of the guide. In these
variations, the axial length of the guide 51 is shorter than the
insertable length of the endoscope 23. The endoscope body 21
includes a steerable distal tip 24 and a proximal controllable
region 28 that is comprised of flexible segments 30. Approximately
half of the length of the endoscope body may be composed of
controllable segments 30, and the remaining proximal part of the
endoscope is flexible passive portion 22. The length of the guide
51 is approximately half that of the endoscope body 23. Although
the guide 51 is freely slidable within lumen 50 of the endoscope 23
in the variation shown, the guide 51 may be preloaded through the
distal end of the endoscope 23 before insertion into the body.
Alternatively, the guide 51 could be positioned as described above.
The guide 51 can be rigidized and held in place by the tensioning
wire 36. The combination of steerable distal tip 24, controllable
proximal portion 28 and guide 51 in this variation of the invention
simplifies the use of the rigidizable guide 51 because the guide 51
only has to be rigidized and locked into position once.
FIG. 2C shows another, slightly magnified, sectional view of the
endoscope of FIG. 2B. This view illustrates an optional suction
device 53, e.g., a negative pressure pump device, which may be
fluidly connected to suction port 202 through suction tube 204.
Suction device 53 is preferably located externally of the patient
during use. Because insufflated air or gas may be trapped within
regions of the colon due to the sacculation and movement of the
colon walls, the suction device 53 may be used to facilitate
removal of these gases as the endoscope is advanced or withdrawn
through the colon. The suction port 202 shown is preferably located
at some point proximal of distal end 24, e.g., approximately one
quarter of the length of the endoscope body 23. This suction port
can be located virtually anywhere along the length of the
endoscope, but it is preferably located such that it does not
interfere with the insufflation process at or near the distal
tip.
FIG. 3A shows an isometric view of a length of the endoscope 20, in
this example part of the proximal portion 22, with a section of the
endoscope body 20 removed for clarity. As seen, a representative
illustration of the guide 36 may be seen disposed within guide
channel or lumen 50 within the proximal portion 22. Lumen 50 may be
an existing working channel, i.e., an access channel for other
tools, or it may be a designated channel for guide 36 depending
upon the desired application. Guide 36 may be inserted within guide
channel 50 through the endoscope handle 32 and pushed proximally
through the remainder of the device, as seen in FIG. 2A; or
preferably, it may be pushed proximally or pulled distally, as
necessary, through a separate guide controller 41, as discussed
above. Although guide 36 is shown in this variation as being
slidably disposed interiorly of endoscope body 20, it may also be
disposed exteriorly of the body 20 to slide along a guide rail or
exterior channel in other variations.
If guide 36 is located within a dedicated channel, such as lumen
50, the distal end of this channel is preferably closed or blocked
at some distal location, e.g., within steerable distal portion 24
or within optional controllable portion 28, to prevent the influx
of bodily fluids within lumen 50. Because an enclosed lumen 50
would further prevent contact of bodily fluids with guide 36, the
amount of cleaning or sterilization of guide 36 is reduced.
If lumen 50 were left as an open channel, additional sterilization
or cleaning and disinfecting of guide 36 and lumen 50 may be
necessary. Alternatively, lumen 50 may be left as an open channel
but configured to have optional closing mechanisms, as shown in the
examples of FIGS. 3B and 3C, taken from FIG. 3A. FIG. 3B shows an
end view of a trap or door 54 which is held within the body of the
instrument and which may be rotated about a pivot 56 in the
direction of the arrow to close access to lumen 50. Trap 54 may be
closed during insertion of the instrument within a patient and then
optionally opened to allow for working tools to be inserted
therethrough. FIG. 3C shows another example where lumen 50 may be
obstructed by an inflatable balloon 59 which may selectively expand
to completely obstruct the passageway. Balloon 59 may be made of
conventional materials and may be held within a compartment or step
58 such that lumen 50 is unobstructed when balloon 59 is deflated.
These examples merely present variations and are not meant to limit
the scope of the invention. Alternative designs and variations are
intended to be within the scope of the present invention.
FIGS. 4A to 4C show variations on possible cross-sections 4A-4A,
4B-4B, and 4C-4C, respectively, taken from FIG. 3A. FIG. 4A shows a
simplified cross-section 22' of a guide 36 having a circular
diameter slidably disposed within proximal portion 22. As seen,
guide 36 may be slidably positioned within channel 50', which may
also be used as a working channel upon removal of guide 36 during,
e.g., a colonoscopy procedure, for providing access for various
instruments or tools to a treatment site. FIG. 4B shows another
possible variation in cross-section 22" where guide 36 is
positioned within channel 50". The variation of the proximal
portion in cross-section 22" may include a number of access lumens
52 optionally formed within the body of the device 20. These lumens
52 may run through the length of device 20 and may be used for
various applications, e.g., illumination fibers, laparoscopic
tools, etc. Although three lumens 52 are shown in the figure, any
number of channels as practically possible may be utilized
depending upon the application at hand. FIG. 4C shows another
variation in cross-section 22'". In this variation, guide 36' may
be formed into a semi-circular or elliptical shape to slide within
a similarly shaped channel 50'". In this example, proximal portion
22'" also includes a working channel 52' which may be shaped
accordingly to fit within the body 22'" along with channel 50'" to
maintain a working channel without having to remove guide 36'. In
any of the above examples, the working or guide channels are
preferably integral structures within the body of endoscope 20.
Having an integral structure eliminates the need for a separate
lumened structure, e.g., a separate sheath, through which guide 36
or any other tools may be inserted. Another variation utilizing
multiple channels and multiple guides will be described in further
detail below. These variations are not intended to be limiting but
are merely presented as possible variations. Other structures and
variations thereof may be recognized by one of skill in the art and
are intended to be within the scope of the claims below.
The structure of the guide may be varied according to the desired
application. The following description on the guide is presented as
possible variations and are not intended to be limiting in their
structure. FIGS. 5A and 5B show cross-sectioned end and side views,
respectively, of a guiding apparatus variation which is rigidizable
by a vacuum force applied within the guide. It is preferable that
the guide is selectively rigidizable, i.e., when the guide assumes
a shape or curve in a flexible state, the guide may be rigidized to
hold that shape or curve for a predetermined period of time.
Although the endoscope structure of the present invention may
utilize a guide which remains in a relatively flexible shape, it is
preferable to have the guide be selectively rigidizable.
Guide 60 may be comprised of two coaxially positioned tubes, outer
tube 62 and inner tube 64, which are separated by a gap 66 between
the two tubes. Inner tube 64 may define an access lumen 68
throughout the length of the tube to provide a channel for
additional tools or other access devices. Both tubes 62, 64 are
preferably flexible enough to be bent over a wide range of angles
and may be made from a variety of materials such as polymers and
plastics. They are also preferably flexible enough such that either
the outer tube 62, inner tube 64, or both tubes are radially
deformable. Once guide 60 has been placed and has assumed the
desirable shape or curve, a vacuum force may be applied to draw out
the air within gap 66. This vacuum force may radially deform inner
tube 64 and bring it into contact with the inner surface of outer
tube 62 if inner tube 64 is made to be relatively more flexible
than outer tube 62. Alternatively, if outer tube 62 is made to be
relatively more flexible than inner tube 64, outer tube 62 may be
brought into contact with the outer surface of inner tube 64.
In another variation, tubes 62, 64 may both be made to be flexible
such that they are drawn towards one another. In yet another
variation, which may be less preferable, a positive force of air
pressure or a liquid, e.g., water or saline, may be pumped into
access lumen 68. The positive pressure from the gas or liquid may
force the walls of inner tube 64 radially into contact with the
inner surface of outer tube 62. In any of these variations, contact
between the two tubular surfaces will lock the tubes 62, 64
together by frictional force and make them less flexible. An
elastomeric outer covering 69, or similar material, may optionally
be placed upon the outer surface of outer tube 62 to provide a
lubricious surface to facilitate the movement of guide 60 within
the endoscopic device. An example of a device similar to guide 60
is discussed in further detail in U.S. Pat. No. 5,337,733, which
has been incorporated herein by reference in its entirety.
Another variation on the guide is shown in FIGS. 6A and 6B which
show cross-sectioned end and side views, respectively, of a guiding
apparatus variation 70 which is rigidizable by a tensioning member
76. Tensioned guide 70 is shown comprised of a series of individual
segments 72 which are rotatably interlocked with one another in
series. Each segment 72 may contact an adjoining segment 72 along a
contacting lip 78. Each segment 72 may further define a channel
therethrough which, collectively along with the other segments 72,
form a common channel 74 throughout a majority of the length of
guide 70. Segments 72 may be comprised of a variety of materials
suitable for sustaining compression forces, e.g., stainless steel,
thermoplastic polymers, plastics, etc.
Proximal and distal segments of guide 70 may hold respective ends
of, tensioning member 76, which is preferably disposed within
common channel 74 through guide 70. Tensioning member 76 may be
connected to a tensioning housing located externally of a patient.
During use when the guide is advanced distally through an endoscope
of the present invention, tensioning member 76 is preferably
slackened or loosened enough such that guide 70 is flexible enough
to assume a shape or curve defined by the endoscope. When guide 70
is desirably situated and has assumed a desired shape, tensioning
member 76 may be tensioned. This tightening or tensioning of member
76 will draw each segment 72 tightly against one another along each
respective contacting lip 78 such that the guide 70 becomes rigid
in assuming the desired shape. A lubricious covering, e.g.,
elastomers, etc., may be optionally placed over at least a majority
of guide 70 to facilitate movement of the guide 70 relative to the
endoscopic device. A similar concept and design is discussed in
further detail in U.S. Pat. No. 5,624,381, which has been
incorporated herein by reference in its entirety.
FIGS. 7A and 7B show cross-sectioned end and side views,
respectively, of a guiding apparatus variation 80 which is
rigidizable by a vacuum force which interlocks individual segments
82. Each segment 82 may be adjoined with adjacent segments by
interlocking ball-and-socket type joints which are preferably
gasketed at the interfaces 86 of each connection. Within each
segment 82, with the exception of the distal segment, may be
defined a channel which is narrowed at one end and flared at the
opposite end. Collectively when the segments 82 are adjoined into
the structure of guide 80, each of the individual channels form a
common channel 84 which extends through at least a majority of the
segments 82 along the length of guide 80. At the proximal end of
guide 80 a vacuum pump, which is preferably located externally of
the patient, is fluidly connected to common channel 84. In use,
once guide 80 is manipulated in its flexible state within the
endoscope to assume the desired shape or curve, ambient pressure
may exist within common channel 84. When the rigid shape of guide
80 is desired, the pump may then be used to create a negative
pressure within common channel 84 and this negative pressure draws
each segment 82 into tight contact with one another to maintain the
desired shape. When the vacuum force is released, each segment 82
would also be released and would thereby allow the guide 80 to be
in its flexible state for advancement or withdrawal. Guide 80 may
further be surrounded by an elastomeric or lubricious covering to
aid in the advancement or withdrawal of the guide 80 within the
endoscopic device.
FIGS. 8A and 8B show cross-sectioned end and side views,
respectively, of yet another guiding apparatus variation 90 which
is optionally rigidizable by either a vacuum force or a tensioning
member which interlocks individual segments 92. Segment 92 may be
in the form of a segmented design with two opposed cups having a
common channel 94 defined therethrough. Between each segment 92 are
ball segments 96 which interfits along a contact rim or area 97
within each adjacent segment 92. Ball segments 96 preferably
contact adjacent cupped segments 96 within receiving channels 98
defined in each cup. When manipulated in its flexible state, guide
90 may be advanced or withdrawn or made to assume a desired shape
or curve. When guide 90 is to be placed into its rigidized shape, a
vacuum force or tensioning member 99 may be utilized in the guide
90 in similar manners as described above. Moreover, guide 90 may
similarly be surrounded by an elastomeric or lubricious covering to
aid in the advancement and withdrawal of the guide 90.
FIGS. 9A and 9B show representative end and side views,
respectively, of another guiding apparatus variation 100. This
variation 100 comprises individual segments 102 having a uniform
sleeve section 104 in combination with an integrated curved or
hemispherical section 106. Each segment 102 is collinearly aligned
with one another with the sleeve section 104 receiving the curved
section 106 of an adjacent segment 102, as shown in FIG. 9C, which
is the cross-section of guide 100 from FIG. 9B. The adjacent
segments 102 may rotate relative to one another over the
sleeve-hemisphere interface while maintaining a common channel 108
through the guide 100. A tensioning member 110 may pass through
channel 108 along the length of guide 100 for compressing the
individual segments 102 against one another when the entire guide
100 is rigidized.
FIG. 10 shows the cross-section of another variation 120 of the
rigidizable guide apparatus. Representative segments are shown
comprising spherical bead segments 122 alternating with sleeve
segments 124. Each of the bead and sleeve segments 122, 124,
respectively, may have a channel defined therethrough which allows
for a tensioning member 126 to be run through the length of guide
120. The alternating segments allow for the rotation of the
adjacent segments while the tensioning member 126 allows for the
compression of the segments against one another when the guide 120
is to be rigidized in much the same manner as described above.
An alternative variation on the rigidizable guide is illustrated in
FIGS. 11A to 11C, which show a stiffening assembly having separate
rigidizable coaxially positioned guides. FIG. 11A shows a
representative number of nested segments 132 in nested stiffening
assembly 130. Each nested segment 132 may be in a number of
different configurations, e.g., ball socket joints, stacked
ring-like segments, etc., with a tensioning member 134 passing
through each of the segments 132. For use with nested assembly 130,
an annular stiffening assembly 140 may be seen in FIG. 11B. Annular
assembly 140, of which only a few representative segments are
shown, are comprised in this variation of annular segments 142
which may be stacked or aligned one atop each other. At least one
tensioning member 144, and preferably at least two, may be passed
through each of the annular segments 142. A central area 146 is
defined in each annular segment 142 such that nested stiffening
assembly 130 may be slidingly placed within the central area 146
defined by the annular stiffening assembly 140. FIG. 11C shows the
stiffening assembly 130 slidingly positioned within annular
stiffening assembly 140 to form the coaxially aligned stiffening
assembly 150. Use of coaxial assembly 150 will be described in
further detail below.
FIGS. 12A and 12B illustrate a variation of the endoscope advancing
through a tortuous path, using an endoscope similar to the
variation of FIG. 2B. FIG. 12A shows a pathway with multiple turns
210, resembling a length of the colon. The distal half of the
device 212 comprises a steerable distal portion 24 and a
controllable proximal portion 28. The guide 51 is slidably held
within a lumen within the endoscope in the relaxed state. As the
device 212 is advanced into the pathway 210, the user steers the
distal tip 24, and the controllable segments 30 follow the curve
selected by the user, navigating the chosen pathway. While in the
relaxed state, the guide 51 may passively assume the shape taken by
the distal portion 24 and the controllable proximal portion 28 as
they are steered along the path. Usually, the user may rigidize
and/or "lock" the guide 51 to assume the curve of the selected
pathway before the controllable proximal portion 28 has advanced
beyond the first curve 220. After being stiffened and locked into
position, the endoscope can continue moving distally while still
maintaining the selected pathway, since the passive flexible
proximal region 22 of the endoscope slides over the rigid guide 51
and conforms to its shape, as shown in FIG. 12B.
After rigidizing the guide, the user can continue to steer the
distal end 24 as it is advanced, and the curves of the selected
pathway are propagated proximally down the controllable segments 30
as the endoscope moves forward. This variation of the device is
capable of conforming to a selected pathway over the entire length
of the endoscope, despite having a shorter guide 51 and
controllable portion 28, since the combined length of the guide 51
and the controllable portion is preferably equal to the length of
the endoscope.
In operation, any of the guiding apparatus as described above or
one recognized by a person of skill in the art to be suitable for
such use as described herein may be utilized. FIGS. 13A to 13H
illustrate a representative method of advancing a colonscopic
device 20 as described herein with a representative guide 36 for
advancement into a patient's colon C. As seen in FIG. 13A, the
steerable distal portion 24 of colonoscope 20 may be first advanced
into the patient's rectum via anus A. The device 20 may be simply
advanced, either manually or automatically by a motor, until the
first curvature is reached or alternatively until the segments of
controllable portion 28 are within colon C. At this point, the
steerable distal portion 24 may be actively controlled by the
physician or surgeon to attain an optimal curvature or shape for
advancement of device 20. The optimal curvature or shape is
considered to be the path which presents the least amount of
contact or interference from the walls of colon C. If the optional
controllable portion 28 is used with the colonoscopic device 20,
once the advancement position 160 has been determined, the device
20 may be advanced further into the sigmoid colon S such that the
automatically controlled segments of controllable portion 28 follow
the distal portion 24 while transmitting the optimal curvature or
shape proximally down the remaining segments of controllable
portion 28.
Alternatively, once steerable distal portion 24 has been steered or
positioned for advancement 160, guide 36 may be advanced distally
in its flexible state along or within device 20 until it reaches a
distal position, i.e., some point distal of the flexible proximal
portion 22 and preferably to the distal end of the device 20, as
shown in FIG. 13B. Preferably, guide 36 is advanced to the distal
end of steerable distal portion 24 or to the distal end of the
optional controllable portion 28, if utilized, or to some point
therebetween. Guide 36 may be advanced to any distal position as
long as a portion of guide 36 attains the optimal curvature or
shape. Prior to advancing the device 20 over guide 36, the guide 36
may be left in its flexible state or it may be optionally
rigidized, as discussed above. If left in its flexible state, guide
36 will still provide desirable column strength to the device 20 as
it is advanced through colon C over the guide 36. It is preferable,
however, that guide 36 is rigidized once it has attained and
conformed to the curvature. As the position of guide 36 is
preferably rigidized and maintained, the device 20 may then be
advanced over the guide 20 in a monorail or "piggy-back" fashion so
that the flexible proximal portion 22 follows the curve held by
guide 36 until the device 20 reaches the next point of curvature.
The following description discusses the use of the optional
controllable portion 28; however, this portion 28 may be omitted
from the device 20.
As shown from FIGS. 13B to 13C, the curve is maintained by guide 36
until the steerable distal portion 24 has been advanced to the
juncture between the sigmoid colon S and the descending colon D. At
this point, the distal portion 24 may be actively steered by the
physician using a variety of visualization techniques, e.g.,
steering via an optional imaging bundle 40 located at the distal
end of the device 20. Once the optimal curve or shape has been
determined, the device 20 may be advanced to position 160. As the
device is moved distally, if the controllable portion 28 is
utilized, portion 28 will automatically follow the path set by the
distal portion while the flexible proximal portion follows the
device 20 along the curvature defined by the guide 36. Otherwise,
if controllable portion 28 is omitted, guide 36 will have its
curvature defined solely by steerable distal portion 24. Once the
junction between the sigmoid colon S and descending colon D has
been traversed by the steerable distal portion 24 and the optional
controllable portion 28, the guide may then be relaxed and advanced
distally along the device 20 in its flexible state until it reaches
the distal position in the device 20. As the guide 36 is advanced,
it will attain and conform to a new curvature defined by the
steerable distal portion 24 and/or the controllable portion 28, as
shown in FIG. 13D.
Having attained a new curvature, guide 36 may again be rigidized to
maintain this shape. While the guide 36 maintains this shape, the
device 20 may be advanced further distally along the descending
colon D with the help of the rigidized guide 36 in the piggy-back
manner described above to define the path for the flexible proximal
portion 22 and to prevent excessive contact with the walls of colon
C. As shown in FIG. 13E, the device 20 has been advanced past the
left (splenic) flexure F.sub.1 in the manner described above until
the optional controllable portion 28 has attained the optimal
curvature. The guide 36 may be relaxed again and advanced further
distally in its flexible state, as shown from FIGS. 13E to 13F.
After guide 36 has assumed the desired curvature defined by the
distal portion 24 and/or controllable portion 28, as shown in FIG.
13F, it may again be rigidized and the device 20 may then be
advanced through the transverse colon T and around the right
(hepatic) flexure F.sub.r in much the same manner as described
above and as shown in FIG. 13G. Once the distal portion 24 and the
optional controllable portion 28 has controllably negotiated past
the right (hepatic) flexure F.sub.r, the position of guide 20 may
again be maintained while guide 36 is relaxed once again and
advanced distally to assume the new curvature defined by distal
portion 24 and/or controllable portion 28, as shown in FIG. 13H.
After guide 36 is optionally rigidized again, device 20 may be
advanced 160 completely within the ascending colon G towards the
cecum E for a complete examination of the colon C with minimal
complication and effort.
While the device 20 is advanced through the colon C, the physician
or surgeon may stop the advancement to examine various areas along
the colon wall using, e.g., the imaging bundle 40. During such
examinations, the guide 36 may be temporarily withdrawn manually or
automatically from the device 20 to allow for the insertion of
other tools through the guide channel 50. After a procedure has
been completed on the colon wall, the tool may be withdrawn from
guide channel 50 and guide 36 may be reintroduced into the device
20 so that the device may optionally be advanced once again into
colon C.
To withdraw device 20 from within the colon C, the procedure above
may be reversed, as shown in FIG. 14A, such that the withdrawal 162
minimally contacts the walls of colon C. Alternatively, guide 36
may simply be removed from device 20, as shown in FIG. 14B, while
leaving device 20 within colon C. The device 20 may simply be
withdrawn by pulling the proximal portion 22 to remove the device
20. This method may rub or contact the device 20 upon the walls of
colon C, but any impingement would be minimal.
An alternative method of advancing an endoscope through a tortuous
path may be seen in FIGS. 15A to 15C by using the rigidizable guide
assembly 150 seen from FIG. 11C. FIG. 15A shows a pathway to be
negotiated by endoscopic device 172. The pathway may represent a
portion of colon 170. As device 172 is desirably steered to assume
a curve, nested stiffening assembly 130 may be advanced distally
within device 172 to distal end 174 while in a relaxed state.
Alternatively, nested assembly 130 may be advanced in the flexible,
relaxed state along with the distal end 174.
Once the curve has been selected, nested assembly 130 may be
stiffened to maintain its shape. At this point, annular stiffening
assembly 140 may be advanced over nested assembly 130 towards
distal end 174. Once assembly 140 has assumed the curve defined by
assembly 130, annular assembly 140 may then be rigidized and nested
assembly 130 may be relaxed into its flexible state, as shown in
FIG. 15B. Then the distal end 174 may be further advanced with or
without assembly 130 while being pushed along the curve defined by
rigidized annular assembly 140, as shown in FIG. 15C. Once distal
end 174 of device 172 has negotiated the curve, nested assembly
130, after being advanced to distal end 174, may then be rigidized
again and annular assembly 140 may be relaxed and advanced again
over assembly 130 and so on until the desired treatment location
has been reached within the body.
Another alternative variation on advancing an endoscope through a
tortuous path may be seen in FIGS. 16A to 16E. This variation uses
multiple guides which may be alternately rigidized while being
advanced distally along the path. FIG. 16A shows a portion of the
curved pathway in colon 170 with endoscope 180 being advanced
therethrough. Multiple guides may be used in this variation, but
preferably two guides are utilized, as described below. Any one of
the rigidizable guide variations discussed herein may be used
solely or in combination with different types of guides in the same
device 180. Each guide may be advanced within its own lumen defined
within the endoscope, or they may also share a common dedicated
lumen.
As device 180 approaches a curvature of colon 170, first guide 184
may be advanced towards the steerable distal end 182. While being
advanced, first guide 184 is in a relaxed and flexible state
allowing it to conform to the shape defined by the distal end 182.
Having been advanced to distal end 182, as shown in FIG. 16B, first
guide 184 is rigidized to maintain the shape defined by the
steerable distal end 182. Device 180 may then be advanced further
distally into colon 170 while riding over rigidized first guide
184.
After device 180 has been further advanced to a new position,
second guide 186 may also be advanced distally in its relaxed state
through device 180 up to the distal end 182 while first guide 184
is preferably still rigidized, as shown in FIG. 16C. As second
guide 186 advances, it may conform to a new shape defined by device
180. Second guide 186 may then be rigidized to hold its shape.
First guide 184 may be relaxed but its rigid shape is preferably
also maintained while the distal end 182 of device 180 is further
advanced distally through colon 170, as shown in FIG. 16D.
After device 180 has been advanced distally, first guide 184 may be
relaxed and advanced through device 180 up to distal end 182 while
the rigidity of second guide 186 is maintained, as shown in FIG.
16E. Second guide 186 may be relaxed and then advanced in its
flexible state distally through device 180 and so on. This process
may be repeated as device 180 is required to negotiate arbitrarily
tortuous paths.
Although the endoscope of the present invention has been described
for use as a colonoscope, the endoscope can be configured for a
number of other medical and industrial applications. In addition,
the present invention can also be configured as a catheter,
cannula, surgical instrument or introducer sheath that uses the
principles of the invention for navigating through tortuous body
channels. The present invention may also be used for industrial
applications such as inspection and exploratory applications within
tortuous regions, e.g., machinery, pipes, etc.
In a variation of the method that is particularly applicable to
laparoscopy or thoracoscopy procedures, the steerable endoscope can
be selectively maneuvered along a desired path around and between
organs in a patient's body cavity. The distal end of the endoscope
may be inserted into the patient's body cavity through a natural
opening, through a surgical incision or through a surgical cannula,
introducer, or trocar. The selectively steerable distal portion can
be used to explore and examine the patient's body cavity and to
select a path around and between the patient's organs. The
electronic motion controller in conjunction with the tracking rod
can be used to control the automatically controlled proximal
portion to follow the selected path and allow the rest of the body
to follow the tracking rod and, if necessary, to return to a
desired location using the three-dimensional model in the
electronic memory of the electronic motion controller. Modification
of the above-described assemblies and methods for carrying out the
invention, and variations of aspects of the invention that are
obvious to those of skill in the art are intended to be within the
scope of the claims.
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